Auto-alignment systems are used with active and passive electro-optic sensors to maintain pointing in a selected direction and to stabilize the line-of-sight of the sensors. The auto-alignment system typically includes a laser source that generates the auto-alignment beam and a sensor for detecting the auto-alignment beam. Auto-alignment systems can require high speed beam sensing to measure and correct for system misalignment. High resolution typically comes with poor measurement range or requires large pixelated arrays to perform the auto-alignment beam sensing. Many conventional systems for sensing/tracking the auto-alignment beam rely on locating the centroid of a focused spot. Position sensing detectors (PSDs) measure the location of the centroid in two dimensions. A commonly used type of PSD is a so-called “quad cell” that is a 2×2 array of four high-speed photodiodes. For PSDs, there is generally a trade-off between angular resolution and range, and a disadvantage of a quad cell PSD is usually small range of measurement. The quad cell is optimal for maintaining the focus spot at one location. Larger measurement ranges can be achieved using a segmented PSD, which is essentially an array of quad cells. With this type of PSD, increased range comes with larger overall detector size and higher cost. Alternatively, larger measurement ranges can be achieved using a lateral effect PSD, which gives a linear voltage output that corresponds to the location of the focused spot on the diode. Lateral effect PSDs are common for visible and shortwave infrared (SWIR) applications, but do not exist for longwave infrared (LWIR).